"Zhang, Chen" <chen.zh...@intel.com> wrote: >> -----Original Message----- >> From: Vladimir Sementsov-Ogievskiy <vsement...@yandex-team.ru> >> Sent: Thursday, May 4, 2023 4:23 PM >> To: Zhang, Chen <chen.zh...@intel.com>; qemu-devel@nongnu.org >> Cc: lukasstra...@web.de; quint...@redhat.com; Peter Xu >> <pet...@redhat.com>; Leonardo Bras <leob...@redhat.com> >> Subject: Re: [PATCH v4 09/10] migration: disallow change capabilities in COLO >> state >> >> On 04.05.23 11:09, Zhang, Chen wrote: >> > >> > >> >> -----Original Message----- >> >> From: Vladimir Sementsov-Ogievskiy <vsement...@yandex-team.ru> >> >> Sent: Saturday, April 29, 2023 3:49 AM >> >> To: qemu-devel@nongnu.org >> >> Cc: lukasstra...@web.de; quint...@redhat.com; Zhang, Chen >> >> <chen.zh...@intel.com>; vsement...@yandex-team.ru; Peter Xu >> >> <pet...@redhat.com>; Leonardo Bras <leob...@redhat.com> >> >> Subject: [PATCH v4 09/10] migration: disallow change capabilities in >> >> COLO state >> >> >> >> COLO is not listed as running state in migrate_is_running(), so, it's >> >> theoretically possible to disable colo capability in COLO state and >> >> the unexpected error in migration_iteration_finish() is reachable. >> >> >> >> Let's disallow that in qmp_migrate_set_capabilities. Than the error >> >> becomes absolutely unreachable: we can get into COLO state only with >> >> enabled capability and can't disable it while we are in COLO state. >> >> So substitute the error by simple assertion. >> >> >> >> Signed-off-by: Vladimir Sementsov-Ogievskiy >> >> <vsement...@yandex-team.ru> >> >> --- >> >> migration/migration.c | 5 +---- >> >> migration/options.c | 2 +- >> >> 2 files changed, 2 insertions(+), 5 deletions(-) >> >> >> >> diff --git a/migration/migration.c b/migration/migration.c index >> >> 0d912ee0d7..8c5bbf3e94 100644 >> >> --- a/migration/migration.c >> >> +++ b/migration/migration.c >> >> @@ -2751,10 +2751,7 @@ static void >> >> migration_iteration_finish(MigrationState *s) >> >> runstate_set(RUN_STATE_POSTMIGRATE); >> >> break; >> >> case MIGRATION_STATUS_COLO: >> >> - if (!migrate_colo()) { >> >> - error_report("%s: critical error: calling COLO code without " >> >> - "COLO enabled", __func__); >> >> - } >> >> + assert(migrate_colo()); >> >> migrate_start_colo_process(s); >> >> s->vm_was_running = true; >> >> /* Fallthrough */ >> >> diff --git a/migration/options.c b/migration/options.c index >> >> 865a0214d8..f461d02eeb 100644 >> >> --- a/migration/options.c >> >> +++ b/migration/options.c >> >> @@ -598,7 +598,7 @@ void >> >> qmp_migrate_set_capabilities(MigrationCapabilityStatusList *params, >> >> MigrationCapabilityStatusList *cap; >> >> bool new_caps[MIGRATION_CAPABILITY__MAX]; >> >> >> >> - if (migration_is_running(s->state)) { >> >> + if (migration_is_running(s->state) || migration_in_colo_state()) >> >> + { >> > >> > Make the "MIGRATION_STATUS_COLO" into the " migration_is_running()" >> is a better way? >> >> I wasn't sure that that's correct.. migration_is_running() is used in several >> places, to do so, I'd have to analyze them all. > > Actually, when running in the "MIGRATION_STATUS_COLO" means QEMU can not > do a normal migration at the same time. > Juan have any comments here?
My understanding of colo is pretty limited, but my mind explodes just trying to think how many things we would have to check/do to do a migration while in colo state. So I guess you are right that we can't be in both at the same time. Later, Juan.